According to Adgey and Pantridge, Liberthson et al, and Hirschman et al, Ventricular Asystole or severe Ventricular Bradycardia is responsible for 16 to 25% of all pre-hospital cardiac arrest. These cases have been 100% fatal in Adgey and Pantridge's series. Emergency treatment of in-hospital heart block by direct percutaneous implantation of fine insulated electrode pacing wires into the right ventricle was developed previously and used in over 100 cases. Analysis of the first 25 cases indicated a 95% success rate in pacing. It will be the objective of this project to: 1) determine the incidence of severe ventricular bradycardia (V.R. less than 40/min.) and ventricular asystole as the cause of pre-hospital cardiac arrests; 2) to determine the feasibility of treating the above type of pre-hospital cardiac arrest by direct percutaneous wire pacing; 3) to train MICU personnel to implant pacer wires if feasibility can be established; and 4) evaluate effectiveness of percutaneous wire pacing undertaken by specially trained MICU paramedics. Initially, either the principal investigator or a trained physician will respond to selected medical calls and go with the paramedics to the scene of the arrest. In the event ventricular asystole or severe bradycardia is recognized, cardiopulmonary resuscitation will be carried out immediately and Atropine and Epinephrine will be given parentally. If cardiac rhythm cannot be restored or if an IV line cannot be established, pacing wires will be implanted directly into the heart via the xiphoid approach and attempts will be made to pace the heart artificially. If feasibility of this approach can be established, a training program will be initiated for the Paramedic Mobile Intensive Care Unit. Recommendations will be made to amend State laws and the effectiveness of this pilot program will then be evaluated during a six-month period.